179 FEHMCm : GEOLOGY AND COAL RESOURCES OF KOREA, C. P. 
sandstone, so that the latter forms an overhanging cliff or barrier 
(see Plate 27, fig. 2) ; in places the coal series is eroded far 
enough backwards to give rise to a cave, in which the coal itself 
forms a part of the walls whilst loose blocks of sandstone fallen 
from the roof often litter the floor. In one case (Biyah Mandha 
Nala — Sanhat, No. 14) the erosion of the coal has given rise to 
a flat cave some 3 to 5 feet high extending inwards for 60 yards, 
where there is a small inlet from the bed of the dry water-course 
above, part of the water in the rains evidently passing over the 
fall, and a smaller portion through the cave itself. In the smaller 
stream-beds there is as a rule no water in the dry season, but in 
the larger streams and rivers there is every gradation from a 
mere trickle over the edge of the fall, to a fine waterfall. These 
falls, whether dry or provided with water, are locally known as 
ghdg, ■ the finest I saw, and I believe the finest in the State, 
being the Kirwahi Ghag on the Hasdo River figured in Plate 28. 
The height of the fall is aboiit 75 feet, and the river here has 
eroded in the sandstone and underlying coal series a magnificent 
cirque some 200 yards across. 
In prospecting for coal, therefore, it is necessary to examine 
the base of each of these ghags or barriers, coal being often found 
where not otherwise indicated by peering between the sandstone 
blocks that sometimes fitter the base of these falls. 
As might be anticipated, both the deep ravines noticed earfier, 
and these ghags, are often profusely adorned with moisture-and- 
shade-loving plants, such as ferns, mosses, and 
Ferns, stalactites, etc. , t i i i • x t 
liverworts. Indeed, nowhere m India, not 
even in the moist parts of Sikkim, nor in the Nilgiris, have I noticed 
a greater variety of ferns, and a botanist would probably be amply 
rewarded by a visit to the coal terrains of this part of India. 
Stalactites, also, — though always of small size (up to 6 inches 
long) — are not infrequent in the under-cut caves. 
As would be expected in a part inhabited by aboriginal tribes 
(Bhuinhars, Gonds, etc.), to whom most of the secrets of the 
jungles are known, each of these ghags and caves has a distinctive name, 
derived, usually, from some physical feature or tradition ; this 
name is frequently extended to the stream itself, or to a section 
of it until another barrier or some other natural feature leads to 
a change of designation. 
